11 SPECIALIZED COMMUNICATIONS

RADIO TELETYPEWRITING (RTTY)

RTTY is the data communications mode with the longest history. It was originally designed for use with mechanical teletypewriters which were often used before personal computers became common. Now you can easily start operating RTTY with a personal computer and MCP. Unlike Packet, each time you type a letter, it is transmitted over the air. What you typed is transmitted and displayed on the computer screen of the recipient.

RTTY operation uses frequency shift keying (FSK) and the 5-bit Baudot code or the 7-bit ASCII code to transmit information.

For the cable connections, see “RTTY” {page 95}.

For further information, consult reference books about Amateur Radio.

1Access Menu No. 38 and select an FSK shift.

•FSK shift is the difference in frequencies between a mark and a space.

•The 170 Hz default is used on the Amateur bands.

2Access Menu No. 39 and select a key-down polarity.

•Select “NORMAL” to transmit a mark when keying down or “INVERS” to transmit a space. The default is “NORMAL”.

3Access Menu No. 40 and select high tone (2125 Hz) or low tone (1275 Hz) for mark.

•High tone (default) is commonly used nowadays.

4Select an operating frequency.

5Press [CW/ FSK/ REV] to select FSK.

•“FSK” appears.

6If necessary to be compatible with the other station, press [FUNC], [CW/ FSK/ REV] to reverse the transceiver to the upper sideband.

• “FSR” appears.

7Following the instructions provided with your MCP, enter a command from your computer to select transmit mode.

•The MAIN band LED changes from green (RX) to red (TX).

•You may instead press [SEND] to manually select the transmit mode.

8Begin sending data from your computer.

•Use Menu No. 50C to select the appropriate AF output level. The AF control cannot be used for this adjustment.

•Press [FUNC], [PWR/ TX MONI] to monitor your signals. Press [FUNC], [PWR/ TX MONI] again to quit this function.

9When finished transmitting, enter a command from your computer to return to receive mode.

•The MAIN band LED changes from red (TX) to green (RX).

•If you pressed [SEND] in step 7, press [SEND] again.

The frequencies (measured in kHz) commonly used for RTTY operation are listed below:

U.S.A./ Canada

ARU Region 1

(Europe/ Africa)

 

 

 

 

 

 

1800

~ 1840

1838

~ 1842

 

 

 

3605 ~ 3645 (DX: 3590)

3580

~ 3620

 

 

 

7080 ~ 7100 (DX: 7040)

7035

~ 7045

 

 

 

 

10140

~ 10150

10140

~ 10150

 

 

14070 ~ 14099.5

14080 ~ 14099.5

 

 

 

 

18100

~ 18110

18101

~ 18109

 

 

 

 

21070

~ 21100

21080

~ 21120

 

 

 

 

24920

~ 24930

22920

~ 24929

 

 

 

 

28070

~ 28150

28050

~ 28150

 

 

 

 

Note: You may adjust the carrier level when necessary. Press [FUNC], [MIC/ CAR] to enter the adjustment mode. With a key down condition, turn the MULTI/ CH control so that the ALC meter reads in the ALC zone but does not exceed the upper ALC zone limit.

•Traditionally, the lower sideband is used for FSK operation.

•Press [FUNC], [CW/ FSK/ REV] to return to the lower sideband.

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